Train dispatching system for railroads



s. N. WIGHT 1,852,550 TRAIN DISPATCHING SYSTEM FOR RAIL ROADS April 5, 1932.

Original Filed Sept. 21, 1927 INVENTOR WATT'ORNEY Patented Apr. 5, 1932 UNITED STATES PATENT OFFICE SEDGWICK N. WIGHT, OF ROCHESTER, SIGNAL COMIPANY,

TRAIN DISPATCHING SYSTEM FOR RAILROADS Original application filed September 21, 1927, Serial No.

Divided and this application filed December 31, 1929.

This invention relates to train dispatching systems, and more particularly to means for indicating the approach of a train within a limited distance of a track switch or other traffic controlling device. This application is a division of my prior application Ser. No. 221,037 filed September 21, 1927, which has matured into Patent N 0. 1,794,567, dated March 3, 1931.

In dispatching the movement of trains on a railway system, and this is true of either single or double track systems, it is desirable to indicate to a local dispatcher or operator when a train has come within a certain distance, say one mile, of the track switch at the end of the distant or the like. It is also desirable to be able to control a switch machine for operating such distant track switch or derail to control the signals associated therewith, and to indicate the passage of a train over a detector track circuit associated with such track switch, as well as the response of the switch machine to its control from the local dispatchers olfice. Further, in the case of a distant switch machine, it is necessary for safety to provide approach locking means to prevent operation of such switch machine in the face of a train approaching at high speed.

In view of the foregoing and other important considerations it is proposed in ac cordance with the present invention to associate these circuit portions and devices that all these functions are obtained with a minimum of line wires. More specifically, it is proposed to combine the approach locking feature with the feature of indicating the approach of a train within an appreciable distance of a track switch in such a way that both of these functions are carried out over the same simple (not multiplex) control circuit extending such distance beyond the track siding, of a derail,

patchers office with such distant track switch. its a further feature it is proposed to not only give a visual indication at the tower as to conditions of traffic and switch machine 221,037. Patent No. 1,794,567, dated March 3,

Serial No. 417,767.

conditions at the distant track switch, but

it is proposed to give a momentary audible indication when an indicating lamp is lighted.

Other objects, purposes and characteristic features of the invention are in part described in the accompanying specification hereinafter, and are in part obvious from the accompanying drawing.

In describing the invention in detail, reference will be made to the accompanying drawing in which be single figure shows an embodiment of the invention illustrating a local dispatchers oflice and a distant track switch on a double track railroad, (i. e. a railroad 011 which traffie travels in one direction only) having associated therewith control and indication apparatus embodying the present invention.

Structure Referring to the drawing the dotted rectangle DO designates a local dispatchers office in which is contained a miniature track layout of which one track switch only has been illustrated, having indicating lamps 4: and 15, and a bell associated therewith, and in which only one lever L, of a bank of levers for controlling distant track switches, derails and signals, has been illustrated. This lever is adapted to control through the line circuit including the line wire and the common return wire C a distant control relay Z,

be. the dis- PA as the case may in combination with lever L and the conditions of traflic at the tant track switch is adapted to control a bell relay BR, which is adapted to control the indicating lamp and the audible signal or hell 5.

In the particular track layout shown the main track comprises rails 6 and 7, which through the medium of track switch 1S diverges into the main track having rails 6 and and the side track having rails 8 and 9 of a passing siding. These tracks are divided into sections by insulated joints 11, of which the section adjacent the track switch comprises the usual detector or fouling track circuit including the track battery 12 and the track relay (conventionally shown by a dotted line) 2DT; the next track section toward the right of which has a track circuit comprising track battery 13 and track relay 1'1; and the third track section ahead includes the track circuit containing the track battery 14 and the track relay 2T.

The track switch 1S is preferably controlled by switch machine SM, which has been conventionally illustrated. Since the particular track layout shown is intended to accommodate trafiic moving in one direction only, that is, consists of aportion of a single track railroad, the main entering signal 1, the take-siding signal 1 and the distant signal 3 only are required in the section shown have been illustrated. In the arrangement shown there is provided an approach indi-- cation relay EA which is normally energized through the following circuit :-beginning at the terminal B of a suitable source of current, front contact 17 of the track relay 3T, wire 18, front contact 19 of the track relay 2T, wire 20, front contact 21 of the track relay 1T, wire 22, winding of the approach indication relay EA, to a common return wire C connected to the other terminal of said source. With the approach indication relay EA energized, and with the signal 1 and 1 at stop the following circuit for the approach locking relay AL is closed :beginning at the terminal B of a suitable source of current, front contact 26 of the approach indication relay EA, wires 27 and 28, winding of the approach locking relay AL, wire 29, signal contact 30 of the signal 1, wire 31, contact 32 of the signal 1, to the common return wire C connected to the other side of said source. With this approaching locking relay AL once energized it will remain energized so long as the signals 1 and 1 remain at stop through the stick circuit including the front stick contact 33 and wire 34. Also, the aproach locking relay AL is energized so long as the detector track relay 2DT is de-energized and the signals 1 and 1 are at stop through the following circuit :beginning at said terminal B, back contact 37 of the detector track relay 2DT, wires 38 and 28, winding of the approach locking relay AL, wire 29, contact 30, wire31 and contact 32 to the common return wire C The purposes of this contact 37 of the detector track relay 2DT is more specifically prior application 120,423 filed July 3, 1926,

v to which reference may be had, and the purposeof which will be more clearly pointed out in connection with the operation of the system.

With the approach indication relay EA energized the relay EX is energized through the following circuit :beginning at the positive terminal of the battery 40, wire 41, front contact 42 of the relay EA, wire 43, winding of the relay EX, wire 44, back to pointed out in my the midpoint of the battery 40. With the detector track relay 213T in its normal energized position the following circuit for the switch machine relay WP is closed :beginning at the plus terminal B of a suitable source of current wire 45, contacts 46 and 47 of the switch machine SM, wire 48, winding of the switch machine relay WP, wire 49, front contact 50 of the detector track relay 2DT, to the common return wire C. \Vith the relays EX, and VP energized the following circuit for the OS-sing relay OS is energized :beginning at the terminal B, front contact 52 of the relay WP, wire 53, front contact 54, of the relay EX, wire 55, winding of the relay OS to the common return wire O connected to the midpoint of said battery. In this connection it should be noted that if relay NP is de-energized and the detector track relay 2DT is energized this same circuit is completed from the negative terminal N of. said battery through front contact 56 of relay 2DT and wire 5?. It is believed that the structure has now been sufheiently described so that the invention is'best understood by considering the operation of the various devices in response to control from the dispatchers office and the response to the movement of trains obtained.

Operation I Let us first assume that there is a train approaching in the normal direction of traffie as indicated by the arrow, but that this train has not yet reached the signal 3, and that the operator is uncertain as to whether this train is to take the main track or the siding, and for this reason he is waiting to be informed when the train reaches the track circuit containing track relay 3T, so that he can compare this fact with other traffic conditions and may from such comparison determine whether the train in question shall take the main track for the siding. As soon as this train moving from right to left treads upon the track circuit containing track relay 31 the energizing circuit for the approach indicating relay EA is broken at the front contact 17 of this track relay 3T. Dropping of the relay EA reverses the polarity applied to the relay EX, so that this relay EX is de-energ'ized for a moment, at least, while the magnetismof its magnetic circuit goes through zero. Momentary deenergization of the relay EX momentarily tie-energizes the relay OS, and momentary deenergization of the relay OS applies current to the line wire 10 leading to the dispatchers oflice DO for a moment only through the following circuit:beginning at the plus terminal of the battery 60, polar contact 61 of the control relay Z, wire 62, back contact 63 of this same relay, wire 64, front contact 65 of the detector track relay 2DT, wire 66, back contact 67 of the relay OS, wires 68 and 10, winding of the line relay LR, wires 69 and 70, contact 71 of the lever L in its neutral position to the common return wire C, which through back contact 72 of relay OS and Wire 78 is connected to the midpoint of the battery 60 The completion of the circuit just traced cil'ects energization of the line relay LR for a moment, and such momentary energization of this relay LR with the lever L in the neutral position closes a pick up circuit for the bell relay which may be traced as follows zbeginning at the positive side of the battery (5, wires 76 and 77, winding of the bell rela BR, wires 7 8 and 79, front contact 80 of the line relay LR, wires 81 and 82, contact 83 of the lever L, wires 8 1 and C, to the midpoint of battery 75. lVith the relay BR once picked up it is stuck up through the following stick circuit z-elements 7-5, 76, 77, BR, 78, 86, 87', 88, 82, 88, 8 1, C, hack to battery 75. With the bell relay ER in its energized condition the indicator and the hell 5 are energized through the following circuit 1- beginning at the terminal B of asuitable battel-y, front contact 90 of the relay BR, wire 91, indicating lamp 15, wire 92, winding of the single stroke hell 5, to the common wire connected to the other side of said battery. The bell 5 is preferably of a construction not including the usual interrupter contact so that the clapper strikes the gong only once for each energization.

The operator is thus informed that the approaching train has entered upon the track circuit containing track relay 3T. It should be remember that the indicating lamp 15 will remain illuminated so long as the dispatcher does not move the lever L. If, however, the dispatcher moves the lever L from the neutral position momentarily and then returns it to the neutral position shown, the stick circuit for the relay ER is momentarily broken and this relay B-s again assumes its deenergized position.

Let us assume that the dispatcher wishes the train in question to continue its westward movement into the main track of the passing siding, and in order to do so moves the lever in a clockwise direction so that the contacts 71 and 83 of this lever engages the stationary contacts 95 and 96, respectively. The engagement of the contact 7'1 with the stationary contact 95 completes an energizing circuit for the control relay Z which may be traced as follows :beginning at the battery 75, wire 70, lever contact 71, wires 70 and 68, winding of the relay LR. wires 10 and 85. front contact 98 of the relay OS, wire 99, winding of the control relay Z to the common return wire C connected to the midpoint of the battery 75. It should be noted that energization of. the line relay LR in this case did not cause the bell relay BR to be picked up because the circuit for the bell relay ER is broken at the lever contact 83. The completion of the circuit for the control relay Z just traced causes the neutral contacts of the relay Z to pick up and causes the polar contacts to remain in the right hand position shown. Since the switch machine SM already assumes the main track position the energization of the control relay Z will not affect the switch machine SM. The picking up of the neutral contact 100 of the relay Z will however complete an energizing circuit to the signal mechanisms of the signal 1 which may be traced as follows :-beginning at the terminal B of a suitable source of current, front contact 100 of the relay Z, wire 101, polar contact 102 of the same relay, wire 103, contacts 104-405 of the switch machine wire 106, signal mechanisms of the sig nal 1 (not specifically shown), wire 107 front contact 108 of the home relay 1H, to the common return wire C connected to the other terminal of said source. lVith this circuit completed the signal 1 will assume its clear proceed condition. In this connection it is desirable to point out that the polar home relay 1H controlled in accordance with the occupancy of the detector taming relay 2DT and the condition of occupancy of the two blocks next in advance thereof, and controls the three position signal 1 accordingly, as shown in my prior application above mentioned. The train in question may thus proceed in a westwardly direction, and if the operator has acted immediately upon the sounding of the bell 5 and has allowed the signal 1 to clear before the train reached the signal 3, been restricted.

When the train in question passes the signal 1 and treads upon the detector track circuit the detector track relay QDT, is de-energized, and thereby due to opening of the contacts and 56 effects de-energization of the relay OS, the de-energization of which causes the control relay Z to be stuck up through the following stick circuit :-beginning at the positive terminal of the battery polar contact 61 of the relay Z, wire 62, neutral contact 63 in the raised postion, wire 110, contact 98 of the relay OS in its retractive positive, wire 99, Winding of the control relay Z, common return wires C and through back contact 72 and wire 73 to the midpoint of the battery 60. The flow of circuit just traced is of the same polarity as that formerly transmitted from the tower DO so that the control relay Z will remain in the right hand energized position. Dropping of the relay OS breaks the line circuit at the contact 98 but connects the line wire 10 to the wire 66 through contact 67, but this circuit is open at the contact of the relay QDT, so that the line circuit from the dispatchers oifice at the distant track switch has current in the illu v AL being stuck up heretofore traced.

' train in the normal direction this train upon the energized position,

" source of current front relay Z, wire 125, same relay Z,

been broken. The opening of the line circuit, as just mentioned, de-energizes the line relay LR at the dispatchers cities, and causes the following circuit to be completed for the indicating lamp l:beginning at the positive terminal of the battery 75, wire 76, contacts -71, wires 70 and 112, back contact 113 of the line relay LR, wire 11 1, lamp 4;, wires 115 and 116, contacts 9683 of the lever L, wire Set to the common return wire C connected to the midpoint of battery 75. The lamp t, will for obvious reasons, remai illuminated so long as the train in question occupies the detector track circuit, after which the lamp 1 is again extinguished. It is desired to point out here that an audible signal similar to the bell 5 may be included in series with the lamp 4, if desired.

Let us now consider the movement of a which the dispatcher after being informed of its approach upon the track circuit containing track relay 3T, may decide to direct into the siding o the passing siding shown. The approach of track circuit containing track relay 3T will eiiect illumination of the indicating lamp 15 at the dispatchers otlice and will cause sounding of the bell 5 for reasons heretofore given. Let us assume that 1 has decided that this train shall take the siding and not the main track. The dispatcher will therefore move the lever L in a counterclockwise direction so as to cause the control relay Z to assume its dotted this because the line wire 10 is now connected to the negative end of the battery 75. Since, as has been assumec, he signal 1 and 1 were both at stop ween the train in question stepped upon the track circuit containing track relay 3T the dropping of the approach indicating relay EA did not effect dropping of the approach locking relay AL, this approach locking relay through its stick circuit With the control relay Z energized to its dotted position the following circuit for operating the switch machine to the take-siding position is completed beginning at the terminal B of suitable contact 120 of the approach locking relay AL, wire 121, front contact 122 of the detector track relay 2DT, wire 123, neutral contact 12 1 of the control polar contact 126, of this eyerse wire B, through the motor of the switch machine (not specifically illusrated), to the common return wire C connected to the terminal of said battery. The completion or" this circuit will cause the the dispatcher 7: switch machine to be operated to the reverse of take-siding position after which this cir cuit will again be opened in the usual way. it should he noted that if either of the signals 1 or 1 had assumed the proceed position that the switch machine SM could not have been operated, because the control circuit therefore, just traced, would have been open at the front contact 120 of the approach locking relay AL. This is true even though the signals 1 and 1 had been thereafter moved tothe stop position,'because with the stick relay AL once de-energized it can only be reenergized by the energization of the relay EA or the de-cnergization of the detector track relay 2DT. In this connection it is desired to point out that if two trains closely follow each other the switch machine may still be operated between the passage of the first and the second train if the lever in the tower is moved to its neutral position so as to prevent clearing of the signals 1 or 1 when the first train has passed. \Vith the signals held at stop, the dropping of the detector track relay 2DT vill through its back contact 37 pick up the approach locking relay A1. This feature of the approach locking has been described in considerable detail in my prior application above mentioned, and it is only the facility of giving approach indication and approach looking over the same circuit and by the same indication relay EA that makes the approach locking portion of the system important in this application.

As the switch machine is operated from one to the other extreme position the energizing circuit for the relay WVP is broken at the switch machine contact 1'? and'a similar circuit applying current of reverse polarity to the relay WP is completed when the switch machine has completed its operating stroke. This of course causes de-energization of the relay P during the period of operation of the switch machine and upon dropping of relay WP causes momentary dropping of the relay OS, and in turn momentary flashing of the indicating lamp l; and similarly picking up of relay P causes momentary dropping of relay OS, which in turn causes momentary dropping of relay LR and momentary fias ing of the indicating lamp 4.

The switch machine SM now having assumed its reverse position and the control relay Z also assuming the reverse position permits the take siding signal 1 to be cleared through the following circuit :beginning at the terminal B by a suitable source 0 current, front contact of the control Z wire 101, polar contact 102 assuming the dotted position, wire 129, contacts 104, 131, wire 132, control mechanism of the signal 1, wire 133, to the common return wire C connected to the other terminal of said source. In this connection it is desired to point out that this circuit may also include the front contact of home relay controlled in accordance with traliic conditions over the siding, in the event that the siding is also track circuited. It is also desired to point out that the signals 1 and 1 and 3 shown are, preferably 3 position signals and have been thus conventionally ioo illustrated, shown, illustrate only how they may be operated to two diii'erent positions.

he arrangement shown and described thus permits a switch machine and signals to be controlled over a single line circuit, over which the response of the switch machine to its control may be indicated, the approach of a train at a distant point, and the passage of a train over a detector track circuit may be indicated over this same line circuit, and in which the passage of the train by the two different points is distinctively indicated by two different indicating lamps. In this connection it should be noted that the passage of a train over the detector track circuit containing relay QDT is never indicated by the indicating lamp 15, because no train is permitted to pass over this detector track circuit unless either the signal 1 or signal 1 is clear, and this is possible only with the control lever L in an extreme position.

The embodiment of the invention just de scribed has been applied to a portion of a double track railroad in which trains normally operate in one direction only, and in such a system it is only necessary to indicate the approach of a train from one direction. If the invention is to be applied to a single track railroad, in which trains run in both directions over the same track, it is preferable to be able to indicate at the tower the approach of a train from either direction, and it is preferable to give these indications distinctively so that the dispatcher is informed as to the direction from which the reported train is approaching.

Having thus shown and described one specific embodiment of the invention and having shown many of the devices forming parts of the novel combinations, conventionally, it is desired to be understood that this has been done for the purpose of simplifying the description of the invention, and has not been done for the purpose of illustrating the scope of the invention nor the exact construction preferably employed in practicing the same; and it is further desired to be understood that various changes, modifications and additions may be made to adapt the invention to the particular problems encountered in practicing the same, all without departing from the scope of the invention or the idea of means underlying the same, except as demanded by the scope of the following claims.

What I claim is 1. In a train dispatching system, the combination with a line circuit connecting a dispatchers oflice and a distant signal including a control relay connected in series in said circuit at the signal end of said circuit and a manually operable lever having a contact connected in series with an indicating relay at the oilice end of said circuit, of another contact on said lever closed when said first indicating relay and line circuit at said ofiice to control said control relay, two indicators at said oflice one of which may be rendered when said indicating relay is deenergized and the other of which may be energized only in response to energization of said indicating relay.

2. A train dispatching system of the wayside signal indicating type comprising, a distaut signal; a control relay for controllin said signal; an indicating relay at a local dispatchers oflice; a lever which to an intermediate and two tions; a circuit including a line and return wire, said indicating relay, said control relay, said lever assuming an extreme position, a source of current located at the dispatchers oitice and one contact located at said wayside signal in series to energize said control relay y movement of said lever and to effect desaid distant signal by opening of said contact; another circuit and return wire, said indicating relay, said lever in its intermediate position, a source of energy located near said distant signal and another contact located near said distant signal in series; whereby said control relay may the dispatchers office and said indicating relay may be de-energized by suming its intermediate position.

3. A train dispatching system of the wayside signal indicating type comprising, a dis tant signal; a control relay for controlling said signal,- an indicating relay at a local dispatchers oflice; a lever which may be moved to an intermediate and two extreme positions; a. circuit including a line and return wire, said indicating relay, said control relay, said lever assuming an extreme position, a source of current located at the dispatchers office and one contact located at said wayside signal in series to energize said control relay by movement of said lever and to effect de-energization of said indicating relay from said distant signal by opening of said contact; another circuit including the same line and return Wire, said indicating relay, said lever in its intermediate position, a contact closed when said control relay is de-energized a source of energy located near said distant signal and another contact located near said distant signal in series; whereby said control relay may be energized from the dispatchers olfice andsaid indicating relay. may

be de-encrgizcd by opening of said one con may be moved tact when said lever is assuming its intermediate position.

4;. A system for controlling a distant track switch comprising; a distant track switch; a. switch machine for operating said track switch; a polar control relay at said switch machine for controlling said switch machine to a position corresponding to the polar position of said control relay; a circuit for said control relay including a line wire, a. return wire, a local indicating relay and a local lever which if in one extreme position includes a source of current of one polarity it in the other extreme position includes a source of current of the reverse polarity in series in said circuit and it in an intermediate position closes said circuit; indicating means rendered active when said indicating relay is de-energized and said lever assumes an extreme position, a contact at said distant switch in series with said control relay for rendering said indicating means active, other indicating means rendered active when said indicating relay is energized and said lever assumes its intermediate position, and means at said distant switch for energizing said indicating relay with said lever in its intermediate position etiective only if said control relay is in its de-energized condition.

5. A system for controlling a distant track switch comprising; a distant track switch; a switch machine for operating said track switch; a polar control relay at said switch machine for controlling said switch machine to a position corresponding to the polar position of said control relay; a circuit for said control relay including a line wire, a return wire a local indicating relay and a local lever which if in one extreme position includes a source of current of one polarity it in the other extreme position includes a source of current of the reverse polarity in series in said circuit and it in an intermediate position closes said circuit; indicating means rendered active when said indicating relay is deenergized and said lever assumes an extreme position, contacts at said distant switch in series with said control relay, means for continuously or intermittently opening said con tacts to render said indicating means distinctively active, other indicating means rendered active when said indicating relay is energized and said lever assumes its intermediate position, and means at said distant switch for energizing said indicating relay with said lever in its intermediate position effective only if said control relay is in its deenergized condition;

6. In a railway switch and signal control layout, the combination with a distant track switch, a signal associated with said track switch, a detector track circuit for said switch, a line'circ'uit connecting a local dis patchers ofiice and said lay-out for controlling said signal subject to tratlic conditions ahead, an approach section separate from said detector track circuit, means for reventing operation of said track switch when said approach section is occupied unless it became occupied after said signal was put to stop,

and means independent of said signal for in.-, dicating occupancy of said approach section over said line circuit.

7. In a railway switch and signal control layout, the combination with a distant track switch, a switch machine for controlling said switch, a signal associated with said track switch, a detector track circuit for said switch, a line circuit connecting a local dispatchers oflice and said lay-out for controlling said switch machine and controlling said signal subject to trafiic conditions ahead, an ap proach section separate from said detector track circuit, means for preventing operation of said track switch when said approach sec,- tion is occupied unless it became occupied after said signal was put to stop, and means independent of said signal for indicating occupancy of said approach section over sai line circuit.

In testimony whereof I afiix my signature.

SEDGWICK N. WIGHT.

DISCLAI MER 1,852,550.Sedgwiclc N. Wight, Rochester, N. Y. TRAIN DISPATCHING SYsTEMs FOR RAILROADS. Patent dated April 5, 1932. Disclaimer filed-October 23, 1934, by the assignee, General Railway Signal Company.

Hereby enters this disclaimer to claims 6 and 7 of said Letters Patent, which are in the following words, to wit:

6. In a railway switch and signal control layout, the combination with a distant track switch, a signal associated with said track switch, a detector track circuit for said switch, a line circuit connecting a local dispatchers ofiice and said lay-out for controlling said signal subject to traffic conditions ahead, and approach section separate from said detector track circuit, means for preventing operation of said track switch when said approach section is occupied unless it became occupied after said signal was put to stop, and means independent of said signal for indicating occupancy of said approach section over said line circuit.

7. In a railway switch and signal control layout, the combination with a distant track switch, a switch machine for controlling said switch, a signal associated with said track switch, a detector track circuit for said switch, a line circuit connecting a local dispatchers office and said lay-out for controlling said switch machine and controlling said signal subject to traflic conditions ahead, an approach section separate from said detector track circuit, means for preventing operation of said track switch when said approach section is occupied unless it became occupied after said signal was put to stop, and means independent of said signal for indicating occupancy of said approach section over said line circuit.

[Ofiicial Gazette November 20, 1.934.] 

